Churches and other meeting halls often use acoustic panels to improve the sound-absorbing characteristics of wall surfaces. These panels typically include rigid insulation panels mounted within a wood frame and covered by a sisal fabric.
The sisal fabric covering used with such panels is mounted by attaching one edge of the fabric to a member of the frame and then manually stretching the fabric taut over the insulation panels. The other edge of the fabric is then attached to the opposite member of the frame.
After a period of time, the covering fabric stretches and begins to sag. Unattractive folds of fabric appear on the acoustic panels and detract from the beauty of the church. To eliminate this sagging the fabric must be removed from the frame and remounted in the same manually-stretched fashion. Since these acoustic panels are frequently mounted at inaccessible heights on the walls of the church, the correction of this fabric sagging problem often requires the erection of scaffolding, with considerable labor and expense.
Sagging acoustic panel fabric may also be caused by short term changes in the relative humidity. Such temporary sagging is generally tolerated by churches, despite the poor appearance of the acoustic panels, because of the costs of repair and likelihood of repeated sagging.
It has been proposed that the sagging problem may be prevented by bonding a stiff fibrous "tectum" board under the sisal fabric. This backing retards the sagging of the fabric, but also reduces the acoustic qualities of the panels by greater than 90 percent.
Accordingly, a need remains for a better system of mounting acoustic panel fabrics.